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llvm-6502/lib/Target/PowerPC/PPCISelDAGToDAG.cpp

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//===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a pattern matching instruction selector for PowerPC,
// converting from a legalized dag to a PPC dag.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "ppc-codegen"
#include "PPC.h"
#include "PPCTargetMachine.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalValue.h"
#include "llvm/Intrinsics.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
//===--------------------------------------------------------------------===//
/// PPCDAGToDAGISel - PPC specific code to select PPC machine
/// instructions for SelectionDAG operations.
///
class PPCDAGToDAGISel : public SelectionDAGISel {
const PPCTargetMachine &TM;
const PPCTargetLowering &PPCLowering;
const PPCSubtarget &PPCSubTarget;
unsigned GlobalBaseReg;
public:
explicit PPCDAGToDAGISel(PPCTargetMachine &tm)
: SelectionDAGISel(tm), TM(tm),
PPCLowering(*TM.getTargetLowering()),
PPCSubTarget(*TM.getSubtargetImpl()) {}
virtual bool runOnMachineFunction(MachineFunction &MF) {
// Make sure we re-emit a set of the global base reg if necessary
GlobalBaseReg = 0;
SelectionDAGISel::runOnMachineFunction(MF);
InsertVRSaveCode(MF);
return true;
}
/// getI32Imm - Return a target constant with the specified value, of type
/// i32.
inline SDValue getI32Imm(unsigned Imm) {
return CurDAG->getTargetConstant(Imm, MVT::i32);
}
/// getI64Imm - Return a target constant with the specified value, of type
/// i64.
inline SDValue getI64Imm(uint64_t Imm) {
return CurDAG->getTargetConstant(Imm, MVT::i64);
}
/// getSmallIPtrImm - Return a target constant of pointer type.
inline SDValue getSmallIPtrImm(unsigned Imm) {
return CurDAG->getTargetConstant(Imm, PPCLowering.getPointerTy());
}
/// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s
/// with any number of 0s on either side. The 1s are allowed to wrap from
/// LSB to MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs.
/// 0x0F0F0000 is not, since all 1s are not contiguous.
static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME);
/// isRotateAndMask - Returns true if Mask and Shift can be folded into a
/// rotate and mask opcode and mask operation.
static bool isRotateAndMask(SDNode *N, unsigned Mask, bool isShiftMask,
unsigned &SH, unsigned &MB, unsigned &ME);
/// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
/// base register. Return the virtual register that holds this value.
SDNode *getGlobalBaseReg();
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
SDNode *Select(SDNode *N);
SDNode *SelectBitfieldInsert(SDNode *N);
/// SelectCC - Select a comparison of the specified values with the
/// specified condition code, returning the CR# of the expression.
SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC, DebugLoc dl);
/// SelectAddrImm - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement [r+imm].
bool SelectAddrImm(SDValue N, SDValue &Disp,
SDValue &Base) {
return PPCLowering.SelectAddressRegImm(N, Disp, Base, *CurDAG);
}
/// SelectAddrImmOffs - Return true if the operand is valid for a preinc
/// immediate field. Because preinc imms have already been validated, just
/// accept it.
bool SelectAddrImmOffs(SDValue N, SDValue &Out) const {
Out = N;
return true;
}
/// SelectAddrIdx - Given the specified addressed, check to see if it can be
/// represented as an indexed [r+r] operation. Returns false if it can
/// be represented by [r+imm], which are preferred.
bool SelectAddrIdx(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering.SelectAddressRegReg(N, Base, Index, *CurDAG);
}
/// SelectAddrIdxOnly - Given the specified addressed, force it to be
/// represented as an indexed [r+r] operation.
bool SelectAddrIdxOnly(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering.SelectAddressRegRegOnly(N, Base, Index, *CurDAG);
}
/// SelectAddrImmShift - Returns true if the address N can be represented by
/// a base register plus a signed 14-bit displacement [r+imm*4]. Suitable
/// for use by STD and friends.
bool SelectAddrImmShift(SDValue N, SDValue &Disp, SDValue &Base) {
return PPCLowering.SelectAddressRegImmShift(N, Disp, Base, *CurDAG);
}
/// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
/// inline asm expressions. It is always correct to compute the value into
/// a register. The case of adding a (possibly relocatable) constant to a
/// register can be improved, but it is wrong to substitute Reg+Reg for
/// Reg in an asm, because the load or store opcode would have to change.
virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
char ConstraintCode,
std::vector<SDValue> &OutOps) {
OutOps.push_back(Op);
return false;
}
void InsertVRSaveCode(MachineFunction &MF);
virtual const char *getPassName() const {
return "PowerPC DAG->DAG Pattern Instruction Selection";
}
// Include the pieces autogenerated from the target description.
#include "PPCGenDAGISel.inc"
private:
SDNode *SelectSETCC(SDNode *N);
};
}
/// InsertVRSaveCode - Once the entire function has been instruction selected,
/// all virtual registers are created and all machine instructions are built,
/// check to see if we need to save/restore VRSAVE. If so, do it.
void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
// Check to see if this function uses vector registers, which means we have to
// save and restore the VRSAVE register and update it with the regs we use.
//
// In this case, there will be virtual registers of vector type created
// by the scheduler. Detect them now.
bool HasVectorVReg = false;
for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
HasVectorVReg = true;
break;
}
}
if (!HasVectorVReg) return; // nothing to do.
// If we have a vector register, we want to emit code into the entry and exit
// blocks to save and restore the VRSAVE register. We do this here (instead
// of marking all vector instructions as clobbering VRSAVE) for two reasons:
//
// 1. This (trivially) reduces the load on the register allocator, by not
// having to represent the live range of the VRSAVE register.
// 2. This (more significantly) allows us to create a temporary virtual
// register to hold the saved VRSAVE value, allowing this temporary to be
// register allocated, instead of forcing it to be spilled to the stack.
// Create two vregs - one to hold the VRSAVE register that is live-in to the
// function and one for the value after having bits or'd into it.
unsigned InVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
unsigned UpdatedVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
const TargetInstrInfo &TII = *TM.getInstrInfo();
MachineBasicBlock &EntryBB = *Fn.begin();
DebugLoc dl;
// Emit the following code into the entry block:
// InVRSAVE = MFVRSAVE
// UpdatedVRSAVE = UPDATE_VRSAVE InVRSAVE
// MTVRSAVE UpdatedVRSAVE
MachineBasicBlock::iterator IP = EntryBB.begin(); // Insert Point
BuildMI(EntryBB, IP, dl, TII.get(PPC::MFVRSAVE), InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::UPDATE_VRSAVE),
UpdatedVRSAVE).addReg(InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(UpdatedVRSAVE);
// Find all return blocks, outputting a restore in each epilog.
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
if (!BB->empty() && BB->back().getDesc().isReturn()) {
IP = BB->end(); --IP;
// Skip over all terminator instructions, which are part of the return
// sequence.
MachineBasicBlock::iterator I2 = IP;
while (I2 != BB->begin() && (--I2)->getDesc().isTerminator())
IP = I2;
// Emit: MTVRSAVE InVRSave
BuildMI(*BB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(InVRSAVE);
}
}
}
/// getGlobalBaseReg - Output the instructions required to put the
/// base address to use for accessing globals into a register.
///
SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
if (!GlobalBaseReg) {
const TargetInstrInfo &TII = *TM.getInstrInfo();
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
DebugLoc dl;
if (PPCLowering.getPointerTy() == MVT::i32) {
GlobalBaseReg = RegInfo->createVirtualRegister(PPC::GPRCRegisterClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
} else {
GlobalBaseReg = RegInfo->createVirtualRegister(PPC::G8RCRegisterClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
}
}
return CurDAG->getRegister(GlobalBaseReg,
PPCLowering.getPointerTy()).getNode();
}
/// isIntS16Immediate - This method tests to see if the node is either a 32-bit
/// or 64-bit immediate, and if the value can be accurately represented as a
/// sign extension from a 16-bit value. If so, this returns true and the
/// immediate.
static bool isIntS16Immediate(SDNode *N, short &Imm) {
if (N->getOpcode() != ISD::Constant)
return false;
Imm = (short)cast<ConstantSDNode>(N)->getZExtValue();
if (N->getValueType(0) == MVT::i32)
return Imm == (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
else
return Imm == (int64_t)cast<ConstantSDNode>(N)->getZExtValue();
}
static bool isIntS16Immediate(SDValue Op, short &Imm) {
return isIntS16Immediate(Op.getNode(), Imm);
}
/// isInt32Immediate - This method tests to see if the node is a 32-bit constant
/// operand. If so Imm will receive the 32-bit value.
static bool isInt32Immediate(SDNode *N, unsigned &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i32) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
/// isInt64Immediate - This method tests to see if the node is a 64-bit constant
/// operand. If so Imm will receive the 64-bit value.
static bool isInt64Immediate(SDNode *N, uint64_t &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i64) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
// isInt32Immediate - This method tests to see if a constant operand.
// If so Imm will receive the 32 bit value.
static bool isInt32Immediate(SDValue N, unsigned &Imm) {
return isInt32Immediate(N.getNode(), Imm);
}
// isOpcWithIntImmediate - This method tests to see if the node is a specific
// opcode and that it has a immediate integer right operand.
// If so Imm will receive the 32 bit value.
static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
return N->getOpcode() == Opc
&& isInt32Immediate(N->getOperand(1).getNode(), Imm);
}
bool PPCDAGToDAGISel::isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
if (isShiftedMask_32(Val)) {
// look for the first non-zero bit
MB = CountLeadingZeros_32(Val);
// look for the first zero bit after the run of ones
ME = CountLeadingZeros_32((Val - 1) ^ Val);
return true;
} else {
Val = ~Val; // invert mask
if (isShiftedMask_32(Val)) {
// effectively look for the first zero bit
ME = CountLeadingZeros_32(Val) - 1;
// effectively look for the first one bit after the run of zeros
MB = CountLeadingZeros_32((Val - 1) ^ Val) + 1;
return true;
}
}
// no run present
return false;
}
bool PPCDAGToDAGISel::isRotateAndMask(SDNode *N, unsigned Mask,
bool isShiftMask, unsigned &SH,
unsigned &MB, unsigned &ME) {
// Don't even go down this path for i64, since different logic will be
// necessary for rldicl/rldicr/rldimi.
if (N->getValueType(0) != MVT::i32)
return false;
unsigned Shift = 32;
unsigned Indeterminant = ~0; // bit mask marking indeterminant results
unsigned Opcode = N->getOpcode();
if (N->getNumOperands() != 2 ||
!isInt32Immediate(N->getOperand(1).getNode(), Shift) || (Shift > 31))
return false;
if (Opcode == ISD::SHL) {
// apply shift left to mask if it comes first
if (isShiftMask) Mask = Mask << Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu << Shift);
} else if (Opcode == ISD::SRL) {
// apply shift right to mask if it comes first
if (isShiftMask) Mask = Mask >> Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu >> Shift);
// adjust for the left rotate
Shift = 32 - Shift;
} else if (Opcode == ISD::ROTL) {
Indeterminant = 0;
} else {
return false;
}
// if the mask doesn't intersect any Indeterminant bits
if (Mask && !(Mask & Indeterminant)) {
SH = Shift & 31;
// make sure the mask is still a mask (wrap arounds may not be)
return isRunOfOnes(Mask, MB, ME);
}
return false;
}
/// SelectBitfieldInsert - turn an or of two masked values into
/// the rotate left word immediate then mask insert (rlwimi) instruction.
SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
DebugLoc dl = N->getDebugLoc();
APInt LKZ, LKO, RKZ, RKO;
CurDAG->ComputeMaskedBits(Op0, APInt::getAllOnesValue(32), LKZ, LKO);
CurDAG->ComputeMaskedBits(Op1, APInt::getAllOnesValue(32), RKZ, RKO);
unsigned TargetMask = LKZ.getZExtValue();
unsigned InsertMask = RKZ.getZExtValue();
if ((TargetMask | InsertMask) == 0xFFFFFFFF) {
unsigned Op0Opc = Op0.getOpcode();
unsigned Op1Opc = Op1.getOpcode();
unsigned Value, SH = 0;
TargetMask = ~TargetMask;
InsertMask = ~InsertMask;
// If the LHS has a foldable shift and the RHS does not, then swap it to the
// RHS so that we can fold the shift into the insert.
if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
Op0.getOperand(0).getOpcode() == ISD::SRL) {
if (Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
} else if (Op0Opc == ISD::SHL || Op0Opc == ISD::SRL) {
if (Op1Opc == ISD::AND && Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
unsigned MB, ME;
if (InsertMask && isRunOfOnes(InsertMask, MB, ME)) {
SDValue Tmp1, Tmp2;
if ((Op1Opc == ISD::SHL || Op1Opc == ISD::SRL) &&
isInt32Immediate(Op1.getOperand(1), Value)) {
Op1 = Op1.getOperand(0);
SH = (Op1Opc == ISD::SHL) ? Value : 32 - Value;
}
if (Op1Opc == ISD::AND) {
unsigned SHOpc = Op1.getOperand(0).getOpcode();
if ((SHOpc == ISD::SHL || SHOpc == ISD::SRL) &&
isInt32Immediate(Op1.getOperand(0).getOperand(1), Value)) {
Op1 = Op1.getOperand(0).getOperand(0);
SH = (SHOpc == ISD::SHL) ? Value : 32 - Value;
} else {
Op1 = Op1.getOperand(0);
}
}
SH &= 31;
SDValue Ops[] = { Op0, Op1, getI32Imm(SH), getI32Imm(MB),
getI32Imm(ME) };
return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops, 5);
}
}
return 0;
}
/// SelectCC - Select a comparison of the specified values with the specified
/// condition code, returning the CR# of the expression.
SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS,
ISD::CondCode CC, DebugLoc dl) {
// Always select the LHS.
unsigned Opc;
if (LHS.getValueType() == MVT::i32) {
unsigned Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt32Immediate(RHS, Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF)), 0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>((int)Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF)), 0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpw cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmplwi cr0,r0,0x5678
// beq cr0,L6
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS, dl, MVT::i32, LHS,
getI32Imm(Imm >> 16)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, Xor,
getI32Imm(Imm & 0xFFFF)), 0);
}
Opc = PPC::CMPLW;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt32Immediate(RHS, Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF)), 0);
Opc = PPC::CMPLW;
} else {
short SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm((int)SImm & 0xFFFF)),
0);
Opc = PPC::CMPW;
}
} else if (LHS.getValueType() == MVT::i64) {
uint64_t Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt64Immediate(RHS.getNode(), Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF)), 0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF)), 0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpd cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmpldi cr0,r0,0x5678
// beq cr0,L6
if (isUInt<32>(Imm)) {
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS8, dl, MVT::i64, LHS,
getI64Imm(Imm >> 16)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, Xor,
getI64Imm(Imm & 0xFFFF)), 0);
}
}
Opc = PPC::CMPLD;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt64Immediate(RHS.getNode(), Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI64Imm(Imm & 0xFFFF)), 0);
Opc = PPC::CMPLD;
} else {
short SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI64Imm(SImm & 0xFFFF)),
0);
Opc = PPC::CMPD;
}
} else if (LHS.getValueType() == MVT::f32) {
Opc = PPC::FCMPUS;
} else {
assert(LHS.getValueType() == MVT::f64 && "Unknown vt!");
Opc = PPC::FCMPUD;
}
return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
}
static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
switch (CC) {
case ISD::SETUEQ:
case ISD::SETONE:
case ISD::SETOLE:
case ISD::SETOGE:
llvm_unreachable("Should be lowered by legalize!");
default: llvm_unreachable("Unknown condition!");
case ISD::SETOEQ:
case ISD::SETEQ: return PPC::PRED_EQ;
case ISD::SETUNE:
case ISD::SETNE: return PPC::PRED_NE;
case ISD::SETOLT:
case ISD::SETLT: return PPC::PRED_LT;
case ISD::SETULE:
case ISD::SETLE: return PPC::PRED_LE;
case ISD::SETOGT:
case ISD::SETGT: return PPC::PRED_GT;
case ISD::SETUGE:
case ISD::SETGE: return PPC::PRED_GE;
case ISD::SETO: return PPC::PRED_NU;
case ISD::SETUO: return PPC::PRED_UN;
// These two are invalid for floating point. Assume we have int.
case ISD::SETULT: return PPC::PRED_LT;
case ISD::SETUGT: return PPC::PRED_GT;
}
}
/// getCRIdxForSetCC - Return the index of the condition register field
/// associated with the SetCC condition, and whether or not the field is
/// treated as inverted. That is, lt = 0; ge = 0 inverted.
///
/// If this returns with Other != -1, then the returned comparison is an or of
/// two simpler comparisons. In this case, Invert is guaranteed to be false.
static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert, int &Other) {
Invert = false;
Other = -1;
switch (CC) {
default: llvm_unreachable("Unknown condition!");
case ISD::SETOLT:
case ISD::SETLT: return 0; // Bit #0 = SETOLT
case ISD::SETOGT:
case ISD::SETGT: return 1; // Bit #1 = SETOGT
case ISD::SETOEQ:
case ISD::SETEQ: return 2; // Bit #2 = SETOEQ
case ISD::SETUO: return 3; // Bit #3 = SETUO
case ISD::SETUGE:
case ISD::SETGE: Invert = true; return 0; // !Bit #0 = SETUGE
case ISD::SETULE:
case ISD::SETLE: Invert = true; return 1; // !Bit #1 = SETULE
case ISD::SETUNE:
case ISD::SETNE: Invert = true; return 2; // !Bit #2 = SETUNE
case ISD::SETO: Invert = true; return 3; // !Bit #3 = SETO
case ISD::SETUEQ:
case ISD::SETOGE:
case ISD::SETOLE:
case ISD::SETONE:
llvm_unreachable("Invalid branch code: should be expanded by legalize");
// These are invalid for floating point. Assume integer.
case ISD::SETULT: return 0;
case ISD::SETUGT: return 1;
}
return 0;
}
SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
DebugLoc dl = N->getDebugLoc();
unsigned Imm;
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
bool isPPC64 = (PtrVT == MVT::i64);
if (isInt32Immediate(N->getOperand(1), Imm)) {
// We can codegen setcc op, imm very efficiently compared to a brcond.
// Check for those cases here.
// setcc op, 0
if (Imm == 0) {
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ: {
Op = SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Op), 0);
SDValue Ops[] = { Op, getI32Imm(27), getI32Imm(5), getI32Imm(31) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
case ISD::SETNE: {
if (isPPC64) break;
SDValue AD =
SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U)), 0);
return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
AD.getValue(1));
}
case ISD::SETLT: {
SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
case ISD::SETGT: {
SDValue T =
SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Op), 0);
T = SDValue(CurDAG->getMachineNode(PPC::ANDC, dl, MVT::i32, T, Op), 0);
SDValue Ops[] = { T, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
}
} else if (Imm == ~0U) { // setcc op, -1
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ:
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(1)), 0);
return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
SDValue(CurDAG->getMachineNode(PPC::LI, dl,
MVT::i32,
getI32Imm(0)), 0),
Op.getValue(1));
case ISD::SETNE: {
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::NOR, dl, MVT::i32, Op, Op), 0);
SDNode *AD = CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U));
return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(AD, 0),
Op, SDValue(AD, 1));
}
case ISD::SETLT: {
SDValue AD = SDValue(CurDAG->getMachineNode(PPC::ADDI, dl, MVT::i32, Op,
getI32Imm(1)), 0);
SDValue AN = SDValue(CurDAG->getMachineNode(PPC::AND, dl, MVT::i32, AD,
Op), 0);
SDValue Ops[] = { AN, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
case ISD::SETGT: {
SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
Op = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops, 4),
0);
return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op,
getI32Imm(1));
}
}
}
}
bool Inv;
int OtherCondIdx;
unsigned Idx = getCRIdxForSetCC(CC, Inv, OtherCondIdx);
SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
SDValue IntCR;
// Force the ccreg into CR7.
SDValue CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
SDValue InFlag(0, 0); // Null incoming flag value.
CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
InFlag).getValue(1);
if (PPCSubTarget.isGigaProcessor() && OtherCondIdx == -1)
IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
CCReg), 0);
else
IntCR = SDValue(CurDAG->getMachineNode(PPC::MFCRpseud, dl, MVT::i32,
CR7Reg, CCReg), 0);
SDValue Ops[] = { IntCR, getI32Imm((32-(3-Idx)) & 31),
getI32Imm(31), getI32Imm(31) };
if (OtherCondIdx == -1 && !Inv)
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
// Get the specified bit.
SDValue Tmp =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops, 4), 0);
if (Inv) {
assert(OtherCondIdx == -1 && "Can't have split plus negation");
return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
}
// Otherwise, we have to turn an operation like SETONE -> SETOLT | SETOGT.
// We already got the bit for the first part of the comparison (e.g. SETULE).
// Get the other bit of the comparison.
Ops[1] = getI32Imm((32-(3-OtherCondIdx)) & 31);
SDValue OtherCond =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops, 4), 0);
return CurDAG->SelectNodeTo(N, PPC::OR, MVT::i32, Tmp, OtherCond);
}
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
SDNode *PPCDAGToDAGISel::Select(SDNode *N) {
DebugLoc dl = N->getDebugLoc();
if (N->isMachineOpcode())
return NULL; // Already selected.
switch (N->getOpcode()) {
default: break;
case ISD::Constant: {
if (N->getValueType(0) == MVT::i64) {
// Get 64 bit value.
int64_t Imm = cast<ConstantSDNode>(N)->getZExtValue();
// Assume no remaining bits.
unsigned Remainder = 0;
// Assume no shift required.
unsigned Shift = 0;
// If it can't be represented as a 32 bit value.
if (!isInt<32>(Imm)) {
Shift = CountTrailingZeros_64(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
// If the shifted value fits 32 bits.
if (isInt<32>(ImmSh)) {
// Go with the shifted value.
Imm = ImmSh;
} else {
// Still stuck with a 64 bit value.
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Intermediate operand.
SDNode *Result;
// Handle first 32 bits.
unsigned Lo = Imm & 0xFFFF;
unsigned Hi = (Imm >> 16) & 0xFFFF;
// Simple value.
if (isInt<16>(Imm)) {
// Just the Lo bits.
Result = CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, getI32Imm(Lo));
} else if (Lo) {
// Handle the Hi bits.
unsigned OpC = Hi ? PPC::LIS8 : PPC::LI8;
Result = CurDAG->getMachineNode(OpC, dl, MVT::i64, getI32Imm(Hi));
// And Lo bits.
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
} else {
// Just the Hi bits.
Result = CurDAG->getMachineNode(PPC::LIS8, dl, MVT::i64, getI32Imm(Hi));
}
// If no shift, we're done.
if (!Shift) return Result;
// Shift for next step if the upper 32-bits were not zero.
if (Imm) {
Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64,
SDValue(Result, 0),
getI32Imm(Shift),
getI32Imm(63 - Shift));
}
// Add in the last bits as required.
if ((Hi = (Remainder >> 16) & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORIS8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Hi));
}
if ((Lo = Remainder & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
}
return Result;
}
break;
}
case ISD::SETCC:
return SelectSETCC(N);
case PPCISD::GlobalBaseReg:
return getGlobalBaseReg();
case ISD::FrameIndex: {
int FI = cast<FrameIndexSDNode>(N)->getIndex();
SDValue TFI = CurDAG->getTargetFrameIndex(FI, N->getValueType(0));
unsigned Opc = N->getValueType(0) == MVT::i32 ? PPC::ADDI : PPC::ADDI8;
if (N->hasOneUse())
return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), TFI,
getSmallIPtrImm(0));
return CurDAG->getMachineNode(Opc, dl, N->getValueType(0), TFI,
getSmallIPtrImm(0));
}
case PPCISD::MFCR: {
SDValue InFlag = N->getOperand(1);
// Use MFOCRF if supported.
if (PPCSubTarget.isGigaProcessor())
return CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32,
N->getOperand(0), InFlag);
else
return CurDAG->getMachineNode(PPC::MFCRpseud, dl, MVT::i32,
N->getOperand(0), InFlag);
}
case ISD::SDIV: {
// FIXME: since this depends on the setting of the carry flag from the srawi
// we should really be making notes about that for the scheduler.
// FIXME: It sure would be nice if we could cheaply recognize the
// srl/add/sra pattern the dag combiner will generate for this as
// sra/addze rather than having to handle sdiv ourselves. oh well.
unsigned Imm;
if (isInt32Immediate(N->getOperand(1), Imm)) {
SDValue N0 = N->getOperand(0);
if ((signed)Imm > 0 && isPowerOf2_32(Imm)) {
SDNode *Op =
CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
N0, getI32Imm(Log2_32(Imm)));
return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
SDValue(Op, 0), SDValue(Op, 1));
} else if ((signed)Imm < 0 && isPowerOf2_32(-Imm)) {
SDNode *Op =
CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
N0, getI32Imm(Log2_32(-Imm)));
SDValue PT =
SDValue(CurDAG->getMachineNode(PPC::ADDZE, dl, MVT::i32,
SDValue(Op, 0), SDValue(Op, 1)),
0);
return CurDAG->SelectNodeTo(N, PPC::NEG, MVT::i32, PT);
}
}
// Other cases are autogenerated.
break;
}
case ISD::LOAD: {
// Handle preincrement loads.
LoadSDNode *LD = cast<LoadSDNode>(N);
EVT LoadedVT = LD->getMemoryVT();
// Normal loads are handled by code generated from the .td file.
if (LD->getAddressingMode() != ISD::PRE_INC)
break;
SDValue Offset = LD->getOffset();
if (isa<ConstantSDNode>(Offset) ||
Offset.getOpcode() == ISD::TargetGlobalAddress) {
unsigned Opcode;
bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
if (LD->getValueType(0) != MVT::i64) {
// Handle PPC32 integer and normal FP loads.
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::f64: Opcode = PPC::LFDU; break;
case MVT::f32: Opcode = PPC::LFSU; break;
case MVT::i32: Opcode = PPC::LWZU; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU : PPC::LHZU; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU; break;
}
} else {
assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::i64: Opcode = PPC::LDU; break;
case MVT::i32: Opcode = PPC::LWZU8; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU8 : PPC::LHZU8; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU8; break;
}
}
SDValue Chain = LD->getChain();
SDValue Base = LD->getBasePtr();
SDValue Ops[] = { Offset, Base, Chain };
// FIXME: PPC64
return CurDAG->getMachineNode(Opcode, dl, LD->getValueType(0),
PPCLowering.getPointerTy(),
MVT::Other, Ops, 3);
} else {
llvm_unreachable("R+R preindex loads not supported yet!");
}
}
case ISD::AND: {
unsigned Imm, Imm2, SH, MB, ME;
// If this is an and of a value rotated between 0 and 31 bits and then and'd
// with a mask, emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRotateAndMask(N->getOperand(0).getNode(), Imm, false, SH, MB, ME)) {
SDValue Val = N->getOperand(0).getOperand(0);
SDValue Ops[] = { Val, getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
// If this is just a masked value where the input is not handled above, and
// is not a rotate-left (handled by a pattern in the .td file), emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRunOfOnes(Imm, MB, ME) &&
N->getOperand(0).getOpcode() != ISD::ROTL) {
SDValue Val = N->getOperand(0);
SDValue Ops[] = { Val, getI32Imm(0), getI32Imm(MB), getI32Imm(ME) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
// AND X, 0 -> 0, not "rlwinm 32".
if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
ReplaceUses(SDValue(N, 0), N->getOperand(1));
return NULL;
}
// ISD::OR doesn't get all the bitfield insertion fun.
// (and (or x, c1), c2) where isRunOfOnes(~(c1^c2)) is a bitfield insert
if (isInt32Immediate(N->getOperand(1), Imm) &&
N->getOperand(0).getOpcode() == ISD::OR &&
isInt32Immediate(N->getOperand(0).getOperand(1), Imm2)) {
unsigned MB, ME;
Imm = ~(Imm^Imm2);
if (isRunOfOnes(Imm, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
N->getOperand(0).getOperand(1),
getI32Imm(0), getI32Imm(MB),getI32Imm(ME) };
return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops, 5);
}
}
// Other cases are autogenerated.
break;
}
case ISD::OR:
if (N->getValueType(0) == MVT::i32)
if (SDNode *I = SelectBitfieldInsert(N))
return I;
// Other cases are autogenerated.
break;
case ISD::SHL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
// Other cases are autogenerated.
break;
}
case ISD::SRL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
}
// Other cases are autogenerated.
break;
}
case ISD::SELECT_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
bool isPPC64 = (PtrVT == MVT::i64);
// Handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
if (!isPPC64)
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
if (N1C->isNullValue() && N3C->isNullValue() &&
N2C->getZExtValue() == 1ULL && CC == ISD::SETNE &&
// FIXME: Implement this optzn for PPC64.
N->getValueType(0) == MVT::i32) {
SDNode *Tmp =
CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
N->getOperand(0), getI32Imm(~0U));
return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32,
SDValue(Tmp, 0), N->getOperand(0),
SDValue(Tmp, 1));
}
SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
unsigned BROpc = getPredicateForSetCC(CC);
unsigned SelectCCOp;
if (N->getValueType(0) == MVT::i32)
SelectCCOp = PPC::SELECT_CC_I4;
else if (N->getValueType(0) == MVT::i64)
SelectCCOp = PPC::SELECT_CC_I8;
else if (N->getValueType(0) == MVT::f32)
SelectCCOp = PPC::SELECT_CC_F4;
else if (N->getValueType(0) == MVT::f64)
SelectCCOp = PPC::SELECT_CC_F8;
else
SelectCCOp = PPC::SELECT_CC_VRRC;
SDValue Ops[] = { CCReg, N->getOperand(2), N->getOperand(3),
getI32Imm(BROpc) };
return CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), Ops, 4);
}
case PPCISD::COND_BRANCH: {
// Op #0 is the Chain.
// Op #1 is the PPC::PRED_* number.
// Op #2 is the CR#
// Op #3 is the Dest MBB
// Op #4 is the Flag.
// Prevent PPC::PRED_* from being selected into LI.
SDValue Pred =
getI32Imm(cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
SDValue Ops[] = { Pred, N->getOperand(2), N->getOperand(3),
N->getOperand(0), N->getOperand(4) };
return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops, 5);
}
case ISD::BR_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
SDValue CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC, dl);
SDValue Ops[] = { getI32Imm(getPredicateForSetCC(CC)), CondCode,
N->getOperand(4), N->getOperand(0) };
return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops, 4);
}
case ISD::BRIND: {
// FIXME: Should custom lower this.
SDValue Chain = N->getOperand(0);
SDValue Target = N->getOperand(1);
unsigned Opc = Target.getValueType() == MVT::i32 ? PPC::MTCTR : PPC::MTCTR8;
unsigned Reg = Target.getValueType() == MVT::i32 ? PPC::BCTR : PPC::BCTR8;
Chain = SDValue(CurDAG->getMachineNode(Opc, dl, MVT::Other, Target,
Chain), 0);
return CurDAG->SelectNodeTo(N, Reg, MVT::Other, Chain);
}
}
return SelectCode(N);
}
/// createPPCISelDag - This pass converts a legalized DAG into a
/// PowerPC-specific DAG, ready for instruction scheduling.
///
FunctionPass *llvm::createPPCISelDag(PPCTargetMachine &TM) {
return new PPCDAGToDAGISel(TM);
}
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